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200+ questions

JavaScript questionsTypeScript supported

200+ JavaScript and TypeScript interview questions, from implementing common library APIs, utility functions, algorithms, to building UI components and more.

Try these popular JavaScript questions

Array.prototype.concatImplement the Array.prototype.concat() method
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JSTS
Array.prototype.filterImplement the Array.prototype.filter() method
Languages
JSTS
Coding Format

Questions List

  • CounterWarm up questionBuild a simple counter that increments whenever a button is clicked
    Available frameworks
  • Mortgage CalculatorBuild a calculator that computes the monthly mortgage for a loan
    Available frameworks
  • TabsBuild a tabs component that displays a list of tab elements and one associated panel of content at a time
    Available frameworks
  • Todo ListBuild a Todo list that lets users add new tasks and delete existing tasks
    Available frameworks
  • Traffic LightBuild a traffic light where the lights switch from green to yellow to red after predetermined intervals and loop indefinitely
    Available frameworks
  • Digital ClockBuild a 7-segment digital clock that shows the current time
    Available frameworks
  • Job BoardBuild a job board that displays the latest job postings from Hacker News
    Available frameworks
  • AccordionBuild an accordion component that a displays a list of vertically stacked sections with each containing a title and content snippet
    Available frameworks
  • Flight BookerBuild a component that books a flight for specified dates
    Available frameworks
  • Generate TableGenerate a table of numbers given the rows and columns
    Available frameworks
  • Progress BarBuild a progress bar component that shows the percentage completion of an operation
    Available frameworks
  • Progress BarsBuild a list of progress bars that fill up gradually when they are added to the page
    Available frameworks
  • Temperature ConverterBuild a temperature converter widget that converts temperature values between Celsius and Fahrenheit
    Available frameworks
  • Accordion IIBuild an accessible accordion component that has the right ARIA roles, states, and properties
    Available frameworks
  • Accordion IIIBuild a fully accessible accordion component that has keyboard support according to ARIA specifications
    Available frameworks
  • Analog ClockBuild an analog clock where the hands update and move like a real clock
    Available frameworks
  • Grid LightsBuild a grid of lights where the lights deactivate in the reverse order they were activated
    Available frameworks
  • Like ButtonBuild a Like button that changes appearance based on the states
    Available frameworks
  • Progress Bars IIBuild a list of progress bars that fill up gradually in sequence, one at a time
    Available frameworks
  • Star RatingBuild a star rating component that shows a row of star icons for users to select the number of filled stars corresponding to the rating
    Available frameworks
  • Tabs IIBuild a semi-accessible tabs component that has the right ARIA roles, states, and properties
    Available frameworks
  • Tabs IIIBuild a fully accessible tabs component that has keyboard support according to ARIA specifications
    Available frameworks
  • Progress Bars IIIBuild a list of progress bars that fill up gradually concurrently, up to a limit of 3
    Available frameworks
  • Tic-tac-toeBuild a tic-tac-toe game that is playable by two players
    Available frameworks
  • Signup FormBuild a signup form that does validation on user details and submits to a back end API
    Available frameworks
  • StopwatchBuild a stopwatch widget that can measure how much time has passed
    Available frameworks
  • Transfer ListBuild a component that allows transferring of items between two lists
    Available frameworks
  • Undoable CounterBuild a counter with a history of the values and ability to undo/redo actions
    Available frameworks
  • Whack-A-MoleBuild a popular arcade game where players attempt to hit moles as they pop up from holes in a board
    Available frameworks
  • Memory GameBuild a memory game where the player needs to match pairs of cards
    Available frameworks
  • Progress Bars IVBuild a list of progress bars that fill up gradually concurrently, up to a limit of 3 and allows for pausing and resuming
    Available frameworks
  • Tic-tac-toe IIBuild an N x N tic-tac-toe game that requires M consecutive marks to win
    Available frameworks
  • Transfer List IIBuild a component that allows transferring of items between two lists, bulk selection/unselection of items, and adding of new items
    Available frameworks
  • WordleBuild Wordle, the word-guessing game that took the world by storm
    Available frameworks